Botanical classification/cultivar designation: Rhododendron simsii xe2x80x98Ospoxe2x80x99. 
The present Invention relates to a new and distinct cultivar of Azalea, botanically known as Rhododendron simsii, and hereinafter referred to by the name xe2x80x98Ospoxe2x80x99.
The new Azalea is a naturally-occurring whole plant mutation of the Rhododendron simsii cultivar Otto, not patented. The new Azalea was discovered by the Inventors in February, 1998, in a controlled environment in Bad Homburg, Germany. The new Azalea was discovered and selected by the Inventors as a flowering plant within a population of plants of the parent cultivar.
Asexual reproduction of the new Azalea by terminal cuttings taken in a controlled environment in Sassenburg, Germany since April, 1999, has shown that the unique features of this new Azalea are stable and reproduced true to type in successive generations.
The new Azalea has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature, daylength and/or light intensity without, however, any variance in genotype.
The following traits have been repeatedly observed and are determined to be the unique characteristics of xe2x80x98Ospoxe2x80x99. These characteristics in combination distinguish xe2x80x98Ospoxe2x80x99 as a new and distinct cultivar:
1. Upright and outwardly spreading plant habit.
2. Glossy and very dark green-colored leaves.
3. Freely branching habit.
4. Red-colored double flowers.
5. Excellent postproduction longevity.
Plants of the new Azalea are most similar to plants of the parent, the cultivar Otto. Plants of the new Azalea differ primarily from plants of the cultivar Otto in flower color.